In situ study of low-temperature dry reforming of methane over La2Ce2O7 and LaNiO3 mixed oxides

Autor(es)

Ramon, Adriana P. ; Li, Xiansheng ; Clark, Adam H. ; Safonova, Olga V. ; Marcos, Francielle C. ; Assaf, Elisabete M. ; van Bokhoven, Jeroen A. ; Artiglia, Luca ; Assaf, Jose M.

• Tipo de documento: Artigo Científico
• Fonte: APPLIED CATALYSIS B-ENVIRONMENTAL; v. 315, p. 16-pg., 2022-06-01.

Resumo

Dry reforming of methane (DRM) is a promising process to generate synthetic gas with a low H-2/CO ratio. The main issues in DRM are the deposition of carbon over the catalyst and active metal sintering. Pyrochlores and perovskites are stable materials with properties that can overcome these challenges due to the presence of well dispersed active metal and oxygen vacancies. La2Ce2O7 and LaNiO3 mixed oxides containing 5 wt% of nickel were synthesized by modified Pechini and hydrothermal methods. The reduction of the La2Ce2O7 and LaNiO3 mixed materials was followed by in situ X-ray diffraction, ambient pressure X-ray photoelectron spectroscopy (APXPS), and X-ray absorption near edge structure. An oxygen-deficient perovskite La2Ni2O5 was identified already at room temperature. Both catalysts were stable during the performance test at low-(600 degrees C) and high-(850 degrees C) temperature DRM reaction, thanks to a negligible carbon accumulation on the catalyst surface. The high amount of electrophilic oxygen species, oxygen vacancies and basic sites detected correlates with the high catalytic activity. The material synthesized by hydrothermal method showed the highest conversion and yield. The better performance in this catalyst was related to higher amount of intermediate basic sites, oxygen vacancies and greater interaction between nickel and cerium. The reaction mechanism proposed in these materials takes into account the intermediates CHx and adsorbed O/OH, which were observed by means of APXPS. (AU)

• Processo FAPESP: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 19/01265-4 - Investigação da superfície de catalisadores pirocloro e seus mecanismos na reforma seca do metano
• Beneficiário: Adriana Paula Ramon
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 15/06246-7 - Aplicação do conceito de biorrefinaria a estações de tratamento biológico de águas residuárias: o controle da poluição ambiental aliado à recuperação de matéria e energia
• Beneficiário: Marcelo Zaiat
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/16329-0 - Produção de gás de síntese a partir de catalisadores com estrutura do tipo pirocloro La2Ce2-xNi0,5xO7-´ através da reação de reforma seca do metano
• Beneficiário: Adriana Paula Ramon
• Modalidade de apoio: Bolsas no Brasil - Doutorado